The present invention relates to methods and apparatus for reaming or boring a hole in a workpiece by means of two oppositely facing tools which are fed towards each other from opposite sides of the hole.
It is previously known to drill holes in workpieces by means of two oppositely faced drills. Such a method is described for instance in British Pat. No. 700,440. The problem to be solved by that patent was that the drilling of holes of considerable length through a component took so long, it was needful to try saving manufacturing time in connection therewith. For the solution of this problem it was proposed to use a pair of oppositely facing, axially aligned drills which are to be fed towards each other until they nearly meet. Thereafter, the feed of one drill is reversed while the other is fed forwardly to drill through the material remaining therebetween. One drawback of such an arrangement is that the drills are not able to pass each other during drilling.
It is, therefore, an object of the present invention to provide novel methods and apparatus for reaming or boring holes from opposite directions.
It is a further object to enable the cutter elements to pass one another during the reaming or boring operation.
An additional object of the invention is to enable holes of oval shape to be formed.